Electric burglar-alarm for safes



(No Model.)

E. J. LELAND. Electric Burglar Alarm for Safes,

No. 230,788. Patented Aug. 3,1880.

INVENTOR JZ/cwz 66 WITNESSES ATTORNEYS.

UNITED STATES PATENT OFFICE.

EDIVIN J. LELAND, OF WORCESTER, MASSACHUSETTS.

ELECTRIC BURGLAR-ALARM FOR SAFES.

PECIFICATION forming part of Letters Patent No. 230,788, dated. August3, 1880.

Application filed May 31, 1880.

To all whom it may concern Be it known that I, EDWIN J. LELAND, ofWorcester, in the county of \Norcester and State of lliassachusetts,have invented a new and useful Improvement in Burglar-Alarms for Safesand Vaults, of which the following is a specification.

My improvements relate to burglar-alarm telegraphs connected with safes,vaults, and similar places. and ar'nnged to give a signal at a centraloffice in case the circuit is broken or the wires tampered with. Suchlines usually have combined with them a galvanometer, so that any changeof resistance caused by an attempt to put a loop in the line, andthereby cut out a safe or vault without breaking circuit, or from anycause, shall be indicated by the galvanometer.

The object of my invention is to provide. means for testing the line atany time and determining whether the safe or vault is in circuit, sothat it will not be necessary to make a personal inspection of the vaultor safe every time the indicator shows a change of resist-- ance or thesignal is operated, as such effects are often produced by crossed wiresand electrical disturbances in the atmosphere.

My invention consists in the combination, with the safe or vault and ofthe closed circuit, of a microphone or other telephonic transmitter andmechanism, such as clock work, to produce audible sounds, these beingplaced within or about the safe or at the locality to be protected andthe transmitter connected in the line, so that the operator at thecentral station may, by the use of a receiver, hear the ticking of theclock so long as the circuit remains unbroken. The transmitter servesalso to convey unusual sounds, so that drilling or other work on thesafe may be detected.

In the accompanying drawing I have illustrated my invention by anelevation of a safe having the alarm apparatus applied thereto.

A is a, safe or vault, of which a, is the door. I) b are the wires of anelectrical circuit, which includes battery B, galvanometer G, andtelephone-receiver It. These circuitwires are extended within the safeor its protectingdoors (No model.)

to the microphone T or other telephonic transmitter and induction-coilI. The circuit-wires will be arranged as usual, so that the circuit isbroken by opening the door of the safe.

'Witl1in the safe or vault, upon the door or other place contiguous tothe transmitter T, is placed a clock movement, (I, or other mechanismdriven by spring or weight or by electricity, for giving an audiblesound. This sound may be simply the ticking ot' the clockmovement, orother devices for giving an audible sound at intervals maybe operated bythe mechanism.

In operation the galvanometer indicates the normal resistance of theline and any variation therefrom, so that any attempts to put a loop inthe line will be indicated by the change of resistai'ice; also, in caseof other wires crossing the line and of electrical disturbances of theatmosphere, the same indication is given; but so long as the saferemains in circuit the ticking of the clock may be heard by use of thereceiver It, and thus the attendant may determine whether thedisturbance occurs from cutting out of the safe or from other causes notrequiring his attention.

Sounds caused by drilling or other work on the safe may also bedetected, and warning thus obtained before the circuit is broken byopening the door.

By thus combining the transmitter with the burglar-alarm the greatestsecurity is given, while much of the trouble arising from false alarmsis saved.

Having thus described my invention, I claim as new and desire to secureby Letters Patent In combination with the circuit-wires of a vault orsafe alarm apparatus, a telephonic transmitter connected in the circuitand clockwork or other mechanism for giving audible sounds,substantially as and for the purposes set forth.

EDWIN J. LELAND.

Witnesses GEORGE E. FRANoIs, E. G. MINARD.

